Patent GB-851061-A (GB)
Title: Preparation of polyesters
IPC: C07F7/00
Filed: 1957-05-27
Abstract: In a process for the manufacture of polyesters by the polycondensation of a bis glycol ester of a dicarboxylic acid, the catalyst used is a certain organic titanate.  This titanate is the reaction product of a simple titanic acid tetra-ester with a polyhydroxy, polycarboxylic or hydroxycarboxylic organic compound and has (a) titanium attached through from two to four of its valence bonds to the residues of an aliphatic, aromatic or araliphatic polyhydric compound, or (b) titanium attached through from one to three of its valence bonds to the residues of an aliphatic, aromatic or araliphatic polycarboxylic acid, or (c) titanium attached through from one to four of its valence bonds to the residues of an aliphatic, aromatic or araliphatic hydroxycarboxylic acid; the remainder of the valencies of the titanium atom in each case being attached to alkoxy, aryloxy, aralkoxy or hydroxyl radicals.  The bi-glycol ester is preferably made by effecting ester-interchange between a dialkyl ester of a di-carboxylic acid and a glycol and this reaction also may be effected in the presence of the titanate as catalyst or in the presence of a mixture of zinc acetate and manganous acetate. Polyesters specified are polyethylene terephthalate, polyethylene isophthalate and ethylene terphthalateethylene isophthalate copolyesters and similar polymers in which the glycol component is propylene glycol or butylene glycol.ALSO:Organic titanium compounds, used as polyesterification catalysts (see Group IV(a)), are made by reacting a tetra-substituted titanate in which the substituents are alkyl and/or aryl and/or aralkyl with (a) a polyhydric alcohol (b) a polycarboxylic acid or (c) a hydroxycarboxylic acid.  The compounds contain (a) titanium attached through from two to four of its valence bonds to the residue of an aliphatic, aromatic or araliphalic polyhydric compound or (b) titanium attached through from one to three of its valence bonds to the residues of an aliphatic, aromatic or araliphatic polycarboxylic acid or (c) titanium attached through from one to four of its valence bonds to the residues of an aliphatic, aromatic or araliphatic hydroxycarboxylic acid; the remainder of the valencies of the titanium atom in each case being attached to alkoxy, aryloxy, aralkoxy or hydroxyl radicals.  The polyhydric compound may, for example, be a glycol, glycerine, pentaerythritol, a polyhydroxy benzene or a hydroxybenzyl alcohol.  The polycarboxylic acid may for example be an oxalic acid, a polymethylene dicarboxylic acid, an aliphatic tricarboxylic acid, an unsaturated dicarboxylic acid, a polycarboxylic acid of the benzene, naphthalene diphenyl, cyclohexane or dicyclohexane series, or diphenyl thio ether-4,41-dicarboxylic acid.  The hydroxycarboxylic acid may be a hydroxyalkane carboxylic acid, a hydroxy benzene carboxylic acid or p-(beta-hydroxyethyl) benzoic acid.  In examples tetraisopropyl or tetrabutyl titanate was reacted in the presence of benzene, toluene or dioxane with (1) ethylene glycol; (2) 1,4-butane diol; (3) decamethylene glycol; (4) glycerol; (5) resorcinol; (6) isophthalic acid; (7) lactic acid; (8) para-hydroxy benzoic acid.